MOSCOW, March 2 (Xinhua) -- Armenian President Robert Kocharianon Sunday called on citizens in the Caucasus state's capital Yerevan to show restraint and understanding at a time when clashes erupted between police and opposition protesters.

"Shots were fired at police, and weapons and grenades...were used (in the conflicts)," Kocharian told a press conference early on Sunday after declaring a 20-day state of emergency in Yerevan, according to reports reaching here.

Kocharian said eight police officers, including a regiment commander, were seriously wounded in the clashes.

The latest reports cited police sources as saying that eight people have been killed in the overnight conflict.

Opposition supporters have been rallying in Yerevan to protest the outcome of the Feb. 19 presidential election, in which Prime Minister Serzh Sargsyan won with 52.8 percent of the vote.

Opposition leader Levon Ter-Petrosyan, who got 21.5 percent of the vote, claimed the vote was rigged and demanded a rerun of the election.

The Armenian government has moved more troops into the capital in the hope of putting situations under control, Itar-Tass news agency reported.